During a Magnetic Resonance Imaging (MRI) image-capturing process using an MRI apparatus, a subject is moved into a bore of a gantry device, while being placed on a couchtop. The gantry device generates a high-frequency magnetic field and a gradient magnetic field on the basis of a pulse sequence corresponding to an image-capturing condition and acquires magnetic resonance signals thereby emitted from the subject.
The gantry device includes, for example, a magnetostatic field magnet that generates a uniform magnetostatic field in the bore and a gradient coil that is provided on the inside of the magnetostatic field magnet and generates a gradient magnetic field in the bore. The magnetostatic field magnet, the gradient coil, and so forth are provided on the outside of a bore tube securing a bore space. Furthermore, a rail etc. on which the couchtop is moved is provided in the bore of the gantry device.
In the gantry device, noise is generated mainly from the gradient coil because of mechanical operations or electromagnetic forces during data acquiring processes. To improve comfortability of subjects during image-capturing processes, such MRI apparatuses that are able to inhibit the noise generated by the gantry device are being developed. Examples of such MRI apparatuses include an apparatus in which the sound released from end faces of an Actively Shielded Gradient Coil (ASGC) is blocked by covering the end faces of the ASGC with lids (sound-blocking lids) that are configured by using a sound-blocking material or a sound-absorbing material. Examples of such MRI apparatuses also include an apparatus in which the gradient coil is stored in a vacuum container.
Furthermore, in recent years, to improve comfortability of subjects during image-capturing processes, such an MRI apparatus that has a large aperture so as to physically make the space inside the bore as large as possible has been developed. However, in view of performance of RF coils and image quality of MRI images, there is a limit to designing apertures of bores to be large.
Because there is a limit to securing physical spaces of bores, attempts have been made by arranging the wall of a bore to be in a bright color such as white and by brightening the wall of a bore with illumination, in order to improve comfortability. However, even with those methods, it is not necessarily possible to prevent subjects from feeling insecure when the subjects are inserted into a bore, and the degree of comfortability which subjects experience when having been moved into a bore was not necessarily sufficient.